Explanation:

- Option 1: Savings of private corporate sector

- This refers to the portion of profits that companies save rather than distribute as dividends. It's similar in concept to undistributed profits.

- Option 2: Reserves and Surplus

- These are funds set aside by a company from its profits for future needs or liabilities. This term encompasses undistributed profits.

- Option 3: Retained Earnings

- This is a direct synonym for undistributed profits. It refers to profits not distributed as dividends but kept in the company for reinvestment.

- Option 4: All of these

- Each term represents the concept of profits remaining in the company rather than being paid out.

The correct answer is: Option 4: All of these

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